 The particles from lava fountains usually cool in the air before hitting the ground, resulting in the accumulation of cindery scoria fragments; however, when the air is especially thick with clasts, they cannot cool off fast enough due to the surrounding heat, and hit the ground still hot, the accumulation of which forms spatter cones.If eruptive rates are high enough, they may even form splatter-fed lava flows.Hawaiian eruptions are often extremely long lived; Puʻu ʻŌʻō, a volcanic cone on Kilauea, erupted continuously for over 35 years.